The present invention relates generally to pressure sensitive label sheets, and, more specifically, to printed label sheets.
Pressure sensitive labels are commonly available in various forms. In a typical embodiment, a label sheet includes several individually removable labels which define an overlay or face sheet adhesively bonded to a release liner. The adhesive is permanently bonded to the back of the overlay, and forms a weak bond with the liner which typically has an exposed silicone surface permitting individual label removal therefrom.
The individual labels are typically defined by full perimeter die cuts which completely sever adjoining labels from their neighbors atop the continuous liner. By lifting the edge of an individual label, the label may be readily peeled away from the liner independently of adjacent labels, with the so removed label then being reattached to another surface using the same adhesive carried on the back of the label for effecting a bond therewith, which is typically permanent.
The adhesive must be suitably tailored in strength for maintaining integrity of the entire label sheet to prevent premature delamination of any of the individual labels thereon, while also permitting individual removal of the labels, with the perimeter die cuts preventing simultaneous multiple label removal.
However, if it is desired to simultaneously remove two or more labels together, the die cuts therebetween may be interrupted by corresponding ties which maintain the continuity of the overlay from label to label without interruption. Several such ties may be spaced apart around the perimeter of adjoining labels so that removal of one label carries with it the so tied adjoining label in a serial strip of labels. The so removed individual labels may then be separated from each other by severing or tearing the joining ties.
In use, labels are printed for various reasons. For example, a pharmacy script is a specialized label sheet having differently sized and configured individual labels for different objectives. Relatively large labels may be used for identifying dispensed drugs and corresponding use instructions. Smaller labels may contain various warnings. And, an associated paper form integrated with the label sheet may include various information regarding the nature of the drug being dispensed and various instructions and warnings.
Pharmacy scripts are available in different configurations for various reasons. The primary objective of the pharmacy script is the labeling of prescription drug containers in a highly competitive industry. Since a typical pharmacy or drugstore dispenses a considerable volume of drug prescriptions each day, the pharmacy script must be easy and fast to use.
In one recently developed pharmacy script, several wide and narrow labels are formed laterally along a thin strip at the leading edge of the label sheet. The leading edge strip defines the feeding direction for the sheet and its orientation so that various information may be printed atop the various labels of the label sheet in the same configuration as multiple sheets are fed through a printer, such as a typical laser printer. In an initial prototype, the various labels contained full perimeter die cuts to ensure the individual removal thereof when desired. The individual labels must be readily removable without delay or damage to maximize the efficiency of label application to their containers.
However, during development and testing of this configuration, premature delamination of portions of the label sheet occurred during sheet transport through the printer. The discovery of this problem and the corresponding solution therefor are the subject of the present invention which prevents premature delamination of the label sheet, while maintaining both the specified configuration thereof including die cut perimeters of the individual labels.